Air-brake apparatus.



H. M. P. MURPHY.

AIR BRAKE APPARATUS.

APPLIUATION FILED MAB. 21. 190s.

Z SHEETS-SHEET 1.

NVENTOR s :s ER

l 5 Allam!) g2 WIZNESSES 'Ns Nokwgs 11E-rens co., wAsMNsrcrf. n c.

H. M. Pl MURPHY.

AIR BRAKE APPARATUS.4 APPLIUATION FILED 141111.21, 190s.

Patented Feb. 16, 1909.

2 SHEETS-SHEET 2.

NVENTOR Allbrney 1w: Hormis Pinks co., WASH/nauw, u Ll UNITED STATES PATENT OFFICE.

HOWARD 'M. P. MURPHY, OF PITTSBURG, PENNSYLVANIA, ASSIGNOR OF ONE-FOURTH TO L. H. BOWMAN, OF MUNHALL, PENNSYLVANIA, AND ONE-EIGHTH TO JOSEPH M. FLAN- NERY, OF PITTSBURG, PENNSYLVANIA.

AIR-BRAKE APPARATUS.

T 0 all whom it may concern.'

Be it` known that I, HOWARD M. P. MUR- PHY, a resident of Fittsburg, in the county of Allegheny and State of Pennsylvania, have invented certain new and useful Improvements in Air-Brake Apparatus 3 and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to improvements in air brake apparatus, and more particularly to such as is adaptable for use in controlling the brakes of a locomotive and its tender,- one object of the invention being to provide a mechanism by means of which the brakes on the locomotive and tender can be operated in unison with or separately from the brakes on the remainder of the train.

A further object is to so construct such mechanism that it shall provide for positive and effective maintenance of any desired brake cylinder pressure regardless of any leakage which might occur from the brake cylinders.

A further object is to provide means for limiting the maximum brake cylinder pressure obtainable in ordinary service applications to a definite degree, but to so construct the mechanism, that in cases of emergency, a much higher pressure can be obtained in the brake cylinders.

A further object is to provide means whereby said high pressure in the brake cylinders can be gradually reduced after a certain length of time, to a lower degree.

A further object is to so construct the mechanism that provision shall be made for ventingfthe train pipe pressure in cases of emergency in order to assist in a rapid reduction of pressure in said train pipe under the conditions above stated.

A further object is to provide in a single structure; simple and efficient means for effecting the application and release of the brakes; means for maintaining any desired ressure in the brake cylinders; means for imiting the degree of brake cylinder pressure obtainable in ordinary service to any predetermined point; means for obtaining a higher brake cylinder pressure in emergency than in ordinary service; means for effecting a gradual reduction of said high pressure in the Specification of Letters Patent.

Application filed March 21, 1908.

Patented Feb. 16, 1909.

Serial No. 422,532.

brake cylinders to a somewhat lower point, and means for venting the brake pipe air to the brake cylinders in cases of emergency.

With these objects in view, the invention consists in certain novel features of construction and combinations of parts as hereinafter set forth and pointed out in the claims.

In the accompanying drawings; Figure 1 is a sectional view (with the piping shown in elevation) showing one embodiment of my invention, the ducts in the manually operated valve devices being shown diagrammatically. Fig. 2 is an enlarged plan View of the seat for the manually-operated valve A. Fig. 2 is an enlarged bottom plan view of the manually operated valve A. Fig. 3 is an enlarged plan view of the seat for the manually-operated valve B. Fig. 3 is an enlarged bottom plan view of the manually opperated valve B. Figs. 4, 5, 6, 7 and 8 are diagrammatical sectional views of the smaller rotary valve and its seat showing how the ports in same are connected, in the various positions of the valve.

l represents a valve casing provided in its upper portion with a chamber 2; in its intermediate portion with a chamber 3, and in its lower portion with an exhaust chamber 4. A passage 5 having an enlarged portion 6, 6 extends from the chamber 2 to the chamber 3, and in the upper portion of this passage, a seat is )rovided for a valve 7 on a rod 8. This ro which extends through the passage 5, is made with grooves or a contracted portion 7a, and at the upper end of said rod, a piston 9 is provide( and movable in the chamber 2, while the lower end of the rod 8 carries a piston 10 movable in the chamber 2, the two pistons 9 and l0 being thus connected so that they will move simultaneously. The chamber 2 receives train pipe ressure above the piston 9, and said cham er receives supply pressure below the piston 9,-the piston 10 in chamber 3 being subjected to brake cylinder pressure on one side and to atmospheric pressure on the other side,-all as hereinafter more fully explained.

In order to prevent a leakage of supply fluid past the piston 9 in the chamber 2 in case the iston packing should become worn or defective, the following instrumentalities are provided: The piston 9 comprises two members, 9a and 9b, the member', 9:L being rigidly secured to the rod 8, and themember. .9b adapted to have a slight movement vindependently thereof.

The member 9b is provided with a tubular stem 11 movable in the tubular upper end oi the rod 8 and passing through said tubular stem 11 is a vvalve rod 12, the lower end of which closes a duct 13 in the rod 8 through which ductand duet 11EL in the tubular stem 11, any excess oi air leaking between the piston members 9 and 9b may pass to the chamber 3 below the piston 1'() andiinally to .theatmosphere The upper end of the valve rod '12 is vprovided witha head 14 disposed in a smallichamber 15 on the piston inemberl 9a and within this chamber, a small spring 16 is located and presses upon the Vhead .14 oi valve rod 12 with a light -force thus preventing the valve 12 from being forced against its seat with a damaging pressure when the piston members 9a and@b are forced close together.

Assume now that the packing ol piston member 9a, should leak, and that the pressure above the piston member 9b is lower 4than the supply pressure 'below the member 9a. Under Vthese conditions, pressure in the vspace 17 between the piston members kwill begin to build up above that inthe upper part ci' chamber 2, and the member 9b oi the piston will Vmove upwardly and unseat the valve 112,-thus permitting the excess of fluid to enter the duct 11a and pass through the 4tubular upperend of the rod S (in which the stem 11 of piston member 9b has a loose lit), and thence through `the duct v13 .to the lower portion of chamber 3, and finally through a duct 18 to the atmosphere. Throughout the operations of applying and releasing the brakes, the piston member 9b will remain balanced as any excess oi' pressure in the space 17 between the piston members will be vented yby the valve 12, and any lack oi:r ressure vin sail space (as will be the case w ien releasing 4the brakes) will be quickly supplied by leakage past the pacling ring of piston member 9b as the space 17 is very small. lt is clear therefore that when the packing oi piston member 9a is perfect the device will operate precisely as it would if the piston .member 9b were removed and the duct 13 closed bya plug.

The casing 1 is provided in its upper portion with a duct 19 with which a pipe 20 communicates for conveying the controlling fluid (through `the medium of a handoperated device hereinafter described) -to the c amber 2 above the piston 9. A'pipe 21 from a main supply source, aconveys supply luid to a duct 22, and, by the latter, such supply iluid is conveyed to the chamber 2 under the Apiston 9. A duct 23 communicates with the portion 6 of passage 5 and through valve chamber 24, with a duct 25, and with `the latter, a pipe 26 leading to the 'brake cylinders communicates.

,Aduct 26a connects the lower part oi chamber 24 with the chamber 3, so that Huid under brake cylinder pressure will enter said chamber 3 above the piston 10, while the duct 18 provides means tor supplying atmospheric pressure below said piston 10.

4The duct 23 is connected, by a duct 27 to the exhaust chamber 4, and in the latter an exhaust valve 28 is located. A spring 29 presses this valve toward its seat and the operation of this valve is controlled by the movements oi the connected pistons 9-10. It is apparent that wien the parts above described, are in the positions shown in the drawings, air can escape from 'the brake vcylinders through duct 25, valve chamber 24,

ducts 23 and 27 to the exhaust chamber 4 and from the latter past the valve 28 te the atmosphere through the port 30. It will also 'be seen that when .the exhaust valve 28 is closed and the valve 7 is o ened (by anexcess of supply pressure unc er the piston 9, over the controlling pressure above said piston), supply luid will pass from `,the lower portion of chamber 2, through the duct 23, valve chamber 24, duct 25fand pipe 26 to the brake cylinder.

r'he .mechanism thus far described, comprises two pistons 9-:10 rigidly connected together so that they will always move in ,unison and valves so arranged that, being controlled lby the movements of the pistons, they provide means for admitting Viuid to and exhausting it from the brake cylinders,-one of the pistons being exposed (on `the side next to the otherpiston) to iluid under supply pressure; the other side `of :the same piston being exposedfto the pressure existing in the controlling pipe 20. The other piston (10) is (as above explained), exposed to bra'lre cylinder pressure on the sidenext to the piston Q and -to atmospheric pressure on the other side. is a result, the brakes can be applied and the cylinder pressure `niaintained by a reduction of pressure in the controlling Ypipe 20 and the upper part of chamber 2 and in the normal (release) position of the mechanism, both pistons will be balanced so that there will be no undue wear Anor friction produced in the preliminary application of the brake.

Assume now that the pressures in the controlling pipe 20 and s upply .pipe 21 are equalized (viz. that the release is full) and that it is desired to put 'a 4certain amount of pressure inthe brake cylinder and to maintain that degree of pressure, notwithstanding any leakage which `might occur from the brake cylinders: This 'may be accomplished by iirst reducing the pressure in the controlling pipe 2() to the Aproper point and then closing this .pipe completely. rllhen the excess of pressure entering the chamber 2 from the source of iluid supply will cause an upward movement .of the pistons 9 and 41.0 until the eXhaust valve 28 is closed by the action of the spring 29. The upward movement of the pistons 9-10 will continue (the lower end of rod 8 leaving the exhaust valve 28) until the valve 7 permits air entering the chamber 2 by the duct 22, to flow from said chamber, through duct 23, valve chamber 24, duct 25 and pipe 26 to the brake cylinders, until the pressure in the latter (which pressure, by reason ofthe duct 26a acts upon the upper side of piston 10), is suilicient to overcome the opposing pressure on the piston 9. The pistons 9 1() will then move downwardly until the valve 7 closes communication between chambers 6 and 6CL and thus prevents the further supply of fluid to the rake cylinders, and the valve 28 opposes the further movement of the pistons because of the spring 29 and the action of the cylinder pressure on the valve 28. 1f the pressure in the brake cylinder falls at all, the upward force acting against the piston 9 will overcome the downward force acting on the piston 10 and the valve 7 will again admit air to the brake cylinders until the desired pressure is again restored. By reducing the ressure in the controlling pipe 20, to a still ower degree, the cylinder ressure will, of course, be increased. Shou d it be desired to release the cylinder pressure, it is simply necessary to increase the pressure in the controlling pipe 20, when the valves will be caused to assume the positions shown in Fig. 1, therelease being then complete if the pressure in the controlline` pipe 20, is fully restored, but only partial if the pressure in the said pipe is only partially restored. Assuming that it is only partially restored,-viz. that there is still a difference of pressure acting against the piston 9 tending to force it upward,-when the pressure of the cylinder air acting on the piston 10 is no longer able to hold the valve 7 in the position shown in Fig. 1, said valve will be moved upwardly until the valve 28 closes and the force exerted by the cylinder pressure and the spring 29 acting on said valve no longer aids in this motion,-thus stopping the exhaust and retaining the desired amount of cylinder pressure. As has been hereinbefore intimated, the valve mechanism shown in the drawings is adapted particularly for use in controlling the operation of the brakes on the locomotive and tenders, and for this reason it is desirable that revision shall be made to limit the brake cy inder pressure in ordinary service operation to some predetermined degree which would be less than it would be possible to obtain from the ordinary supply pressure used. It is also desirable to provide means for obtaining a higher brake cylinder pressure in case of emergency than is obtainable in ordinary service operation, and, after such higher cylinder pressure has been obtained and retained for a specific length of time, to

gradually reduce said pressure to a somewhat lower point. Furthermore, it is advantageous to provide means for venting brake pipe pressure to the brake cylinders in cases of emergency, and also to provide means whereby su'llicient volume of air will be provided to insure the proper operation of the mechanism (which latter would usually be located near the manually operated controlling means) to e'lect the sure and positive operation of the locomotive brakes, particularly when the application of the locomotive brakes is made independently ol' the train brakes.

To accomplish the various ends above enumerated, devices hereinafter described will be employed.

The casing 1 is provided with a chamber 31 having located therein, a piston 32, and this piston is provided with a tubular stem 33 which depends therefrom and is movable in a contracted portion of the chamber 31. The lower end of the stem 33 constitutes a valve 34 for controlling communication between the chambers 31 and 24, and in this valve end of stem 33, small ducts 36 are provided. The piston 32 also constitutes under certain conditions, a valve for closing a duct 37 which communicates at its lower end with the chamber 3l and at its upper end with a chamber 39 in the upper portion of the casing,-said chamber 39 also communicating, through the medium of a duct 4() and a pipe 41 with the train pipe 20a.

One end ol a duct 42 communicates (under certain conditions) with the chamber 39, and such communication is closed by means of a valve 43, pressed toward its seat by means of a spring 44. 'lhe stem 45 of valve 43 passes downwardly through the. chamber b1 and terminates within the tubular stem 33 a short distance above the lower end. of the latter. A spring 46 encircles the stem 45, said spring having an abutment against the u )per wall of the chamber 31 and resting at its lower end upon the lower portion of the tubular stem 33 and thus pressing the valve 34 on its seat.

The duct 42 is adapted to conduct lluid to a chamber 47, but passage of [luid lrom the latter to said duct is prevented'by means of a check valve 4S. A spring 49 presses the valve 4S toward its seat and a rod 49a within the spring, serves to limit the movement of said valve in the other direction. The chamber 47 communicates, by means of a duct 5() with the duet 25 leading to the brake cylinder pipe 26. From this arrangement it will be observed, that when the valve 43 is opened communication is established between from the brake pipe 20, through pipe 41 and duct 4() to chamber 39, and from the latter through duct 42, chamber 47, and ducts 50 and 25 to the brake cylinder pipe 26.

A cage 51 is located within the casing and is inade with a transverse passage 52, which connects the 'chamber 24 with the duct 25 and also Ywith the duct `26?', 'Where-by brake cylinder pressure is radmitted to the `chamber' 3, and this cage is also provided with a vertical lpassage 53, adapted, under certain conditions, to communicate with the valve chamber 24, with which latter, the duct 23 also communicates, Under other conditions, the

passage 53 is closed by means of a piston f spring 55.

Below the cage 5-1, a chamber 56 `isjprovided, and within this chamber, a piston 57 is located. On its upper portion, the wall of the chamber is made with a groove 53 constituting a by pass, and said piston is adapted to be pressed againstra seat 59. A small duct 60 connects the duct "52 in the cage 51 with the space over the piston 57 The' chamber 56 is made with an elongated portion 61 having a vent 62, and the wall of the main portion of chamber 56 is also provided with a series of vents 63 open to the atmosphere.

A tubular stem 64 Vprojects upwardly from the piston 57 and is movable in the cage 51.- A. stem 65 depends from the valve 54 and loosely enters the tubular stem 64 of piston 57. The 'piston 57 is also provided with a rod 66 which depends through the chambers 56-61 and passes freely through a nut 67 adjustable in the lower end of the V'portion 61. A spring 63 encircles the rod 66, and bears at its respective ends aga-inst the piston 57 and the nut 67,-by means of which latter, the tension of said spring can be adjusted. Under normal conditions, the nut 66 willbe protected by means of a cap 69.

t will be observed that the valve 54 is held from its seat by the tension of the adjustable spring 63, and that when the brake cylinder pressure in the duct 25-rises sufficiently to overcome-the resistance oifered by the spring 63, the piston 57 will descend and permit the valve 54 to become seated. Thus the supply of Huid from the duct 23 to the chamber'24 and to the brake cylinders will be stopped, said valve 54 remaining'closed as long as the pressure in the brake cylinders is maintained.

A reservoir 70 is employed for the purpose of providing a sufficient volume of air for insuringthe proper operation of the mechanism, and also to provide means for causing the operation of the piston 32 under certain conditions. This reservoir will therefore be hereinafter referred to as a Ivolume reservoir. A duct 71 communicates with the volume reservoir 70 and also with a chamber 72. The latter communicates, by means of alarge duct 73 with the bottom of the cham- `ber3 1 below the piston 32 and-also with said chamber above the piston 32, Aby-means o f a small duct '7 4. It will be `recalled that the chamber 31 is open toA train pipe pressure through the ducts 37 and 40, and in order to prevent Vthe 'fluid under train pipe pressure from reaching the volume reservoir, a check valve is provided in the bottom of the chamber 72 where `the duct 71 communicates with the latter. In service applications of the -brakes the air from the volume reservoir 7 0 flowing through the small duct 74 passes out to the train pipe, through the ducts 37and 40 but in emergency applications Vof the brakes the pressure in the duct 40 is reduced so rapidly that the small duct 74 is no longer able to keep the pressure on 'the two sides ofthe piston 32 equalized, and

consequently Vthe higher pressure from the volume reservoir, acting against the under side of the `piston 32 (which is freely exposed to saidpressure by duct 73)-causes the latter to rise. When the piston 32 thus rises, it will operate to close the small duct 74 and open a groove or port 76 in the upperportion of the chamber 31, thus venting volumereservoir fluid past piston 32 to the train pipe through -ducts 37 and 40. The upward vmovement ofthe piston 32 will also operate to unseat the valve 43 and permit fluid under train pipe pressure to pass from the train Ypipe duct 40, through the duct 42 past the 'check valve 43, 4through the ducts 50 and 25 to the brake cylinders. The check valve 48 preventsa back Yflow vof air to the train pipe duct 40 when the brake cylinder pressure-is built up. The upward lmovement of the piston 32 also unseats the valve 34, and thus, through the Vducts 36, vexposes the top of the piston valve- 54 tofthe low train pipe-pressure. Irl-consequence of this, the valve 54 cannot close, even though the piston 57 lmoves downvf'ard, because brake cylinder pressure in the lower portion of the valve-chamber 24 holds said valvef54 from its seat.

When the lpressure in the volume-reservoir 76 and in the train pipe duct 40 are nearly equalized, the springs 44 and 46 will return the valve 43 and piston-32, thus closing valve 34 and allowing the valve 54 to be pressed to vits seat by spring 55, as the pressures acting on the upper and lower sides of the valves quickly equalize the leakage of air from one side to the other. The high pressure obtained in the brake cylinder is now reduced by reason Vof the exhaust aforded by Lthe vents 63 (the piston 57 being in a position below said vents) and the said vents are. so located that when subsequently closed by the upward movement of the piston 57, the brake cylinder pressure will have been reduced to some desired point which may be equal to or greater than the maximum amount obtainable in service applications.

The appliances by means of which -the mechanism hereinbefore described can be controlled by the engineer, are shown at the left of Fig. 1 of the drawing and in the various detail views, and embody probably in a single structure, two hand-operated valves A and B, cooperating with various ducts, ports and subordinate valves as hereinafter fully explained.

One purpose of the valve A is to control the pressure in the train pipe and thus to permit the engineer to apply, release and hold the brakes on the whole train when desired and this valve is also adapted to perform certain other service as will hereinafter' be explained. As the valve A controls the train pipe pressure, it is evident that it not only controls the brakes on the cars of a train, but also those on the locomotive when the chamber 2 is connected with the train pipe,-such connection being governed by the valve B. Thus it is evident that when desired, the locomotive brakes and those on the rest of the train may be operated in entire unison by the use of the valve A, when the valve B is left in such position as to provide a connection between the train pipe and chamber 2 at all times.

The purpose of the valve B is to provide means for controlling the brakes on the locomotive and tender independently of those on the cars of the train, and also to operate in conjunction with the valve A to permit, when desired, a release o'f the train brakes independently of those on the locomotive. The valve B is also adapted to provide means for controlling the recharge of the volume reservoir and to connect chamber 2 with said reservoir and to disconnect it from the latter' when desired. These valves, both of which are of the rotary type, are suitably housed within a casing and provided, respectively, with handles A1 B1 for turning them.

A pipe 77 from the main supply reservoir communicates with one end of a duct 78, the other end of which latter communicates with the space within the casing, over the rotary valve A. A pipe 79 which carries a reduced supply pressure, communicates with a duct 80, the latter terminating in a port al and in said duet 8() a check valve 81 is located. A duct 82 connects, through a manually operated plug valve 84, port b1, under valve A, with the train pipe 20a. A duct 83 connects, under certain conditions through manually operated plug valve, 84, duct 82 with a small duct 85, and in the said duct 88, a check valve 86 is located. The duct 85 communicates at one end with the supply pressure duct 78 and at its other end with duct 83 above check valve 86. A duct 85a connects duct 83 above check valve 86 with a chamber 87 over the rotary valve B. A duct 85b connects duct 83, above check valve 86, with the space below the plug cock 84 and thus conveys supply pressure Afluid to said space in order to hold the cock 84 on its seat at all times. A duct 88 connects, through the plug valve 811, a port c1, under valve A with a port a under valve B. The plug valve 84 is provided with a suitable handle 89, by means of which to operate it. A duct 90 communicates at one end with the train pipe duct 82, and at its other end, this duct 90 terminates in .a port b under the valve B. A duct 91 terminates at one end in a port c under valve B and at its other end this duct communicates with a pipe 92, which latter is connected with the volume reservoir 70. The pipe 20 (which as before stated conducts controlling luid through the duct 19 to the chamber 2) communicates with a duct 93, and the latter terminates at its upper end in a port d under the valve B. A duct 94, having a port e at one end is open at its other end to the atmosphere. The various ducts and ports above described are shown in Fig. 1 of the drawings, but other ports, ducts and passages are provided in the valves and their seats. These are shown in the detail views, and their purpose will become apparent in the Jfollowing explanation of the 'functions performed by the various manipulations of the manually operated valves.

The valve A is capable of being set to six definite positions which may be designated by the following terms viz. release, running holding lap, service and emergency Under average conditions, the rotary valve B should be in its running position as shown in Fig. 1 (in which position ports a, c and a' are freely connected) and it may be assumed (during the following explanation) to be in that position until a statement to the contrary is made.

1n release position of the valve A, fluid under main reservoir pressure from the pipe 77 passes through port f1 (which latter extends through valve A) (see Fig. 2a) to port b1 and thence through duct S2 to the train pipe, resulting in rapidly raising the pressure in the latter and consequently releasing the brakes on the train, butv not on the locomotive and tender, because port c1 is closed when the valve A is in this position, and therefore the pressure in the volume reservoir and in the chamber 2 cannot rise,-the check valve (Fig. 1) preventing a flow of air from the chamber 72 to the duct 71. 1n this, release, position of valve A, the cavity d1 of said valve connects ports al and p1, the latter' leading to thc atmosphere and serving as a warning port. A port r1 Fig. 2a (extending through valve A) allows reservoir air to pass to a port h1 which leads to the top of an equalizing piston and to an equalizing reservoir. The piston and reservoir here referred to are not shown in the drawing, as they are quite common in automatic brake valves and .constitute no part of my present invention.

reservoir.)

'In running vposition oic valve A (as shoWnin Fig. l), the cavity d1 connects ports cl and b1 and the cavity d2 in said valve joins port c1 with port t2, which communicates at all times With the portbl, through a passage k1. The cavity d2 also connects ports tl and Z22. Thus it will be seen that liuid under reduced pressure from the pipes 21-79 (supplied through a reducing valve) Will flow from port al to ports l, 52, and thence to the train pipe,-thus releasing the train brakes. As the train `pipe port h1 is also connected With the port c1 the rise of train .pipe pressure Will cause a flow oi air to the .port a, under valve Bythrough passages g andh of said valve B,.to the pipes 20 and 9.2 and thus to the chamber 2 over the piston 9 and to the volume reservoir `70. This `Will effect a release of the locomotive brakes simultaneously with those on the cars of the train.

NOW ii the valve A be moved from running position `to release `or to "holding position, before the pressures in the volume reservoir .70 Yand chamber 2 are restored fully to normal (i. e. the same as the pressure acting on the unser side oi' piston 9), it is evident from the nature oi the application mechanism, that the 4locomotive brakes Will not be iully released. A graduated release of the locomotive brakes Will therefore be permitted, by the use of the valve A alone, it desired, by alternately moving it between ruiming and Hrelease or "holding positions.

ln holding position of the valve A, the cavity dl will still connect ports c1 and b1 and cavity d2 Will still connect ports i12 and h1, but the port c1 will be closed., thus permitting a release of the train brakes and a recharge of their auxiliary reservoirs with reduced pressure, While the locomotive brakes are held applied, as port c1 is closed and therefore the pressure in the volume reservoir and chamber 2 cannot rise.

ln lap position of the valve A, all the ports, except the port c1 are closed, and this port c1 is connected With the port b2 by cavity or passage g1 in order to permit oi` equalization of the train pipe pressure With that in the volume reservoir in easefthese pressures have not yet become equal. 'This lap position of the valve A is used to retain any desired pressure in thetrainpipe.

ln service position cavity or passage g1 ywill connect ports c1 and b2 for the same purpose asin lap posit-ion of the valve. (lt Will be observed that as this connection prow vides Ya free passage between :the volume reservoir 70 and the train pipe, when the cock or plug` valve 84 is open as shown in Fig. l, the check valve '75 `in the mechanism at the right oi Fig, l, Will not rise from .its seat `and Will thus save Wear; when, hoivever, the locomotive is used as a helper, the cock or plug valve'SLl will be closed, andthe air `from jthe volume reservoir 70 will v,pass the check and iloW through chamber 17 2, ducts '74 and 37 to train pipe duct 1l() and thus to the train pipe, in service applications.) ln this (service) position of the valve A, the cavity d2 connects ports h1 and. g1, `the latter leading to the atmosphere. The pressure in the equalizing reservoir (not shown) is thus reduced andthe train pipe pressure slowly vented to' the atmospliere in the usual Way.

ln emergency vposition of the valve A, .the port c1 is closed and cavity e1 connects port b2 through passage e2, cavity m2 and port m1 to the atmospherawthus causing a quick, heavy reduction of train pipe pressure and causing the emergency device in the mechanism at the right of Fig. 1 to operate as hereinbefore explained, and .this action is transmitted by quick-acting triple valves t Lroughout the train. The result is, of course, a quick, powerful application of all brakes on the locomotive and train.

ln the operation or' the controlling valve B,-When said valve is in release :position as shown in Fig. 4, ports a, 't and c are con-V nected .by cavity g and passage lt, thus insuring the equalization oil train pipe and volume reservoir pressure. lPort d leading to the chamber 2 is connected with supply pressure by .port p thus causing a prompt release of the locomotive and tender brakes Without in any Way affecting the train pipe pressure, regardless roi' lthe degree oi th same. As soon as the valve B is moved from release position to any one ci its other positions, communication is again established between the chamber 2 and the volume reservoir Where, because ofthe construction oi` the valve mechanism at the rightoi Fig. l, the pressure cannot be higher (except for a few seconds during an emergency application) than the train pipe pressure, and consequently if the train pipe pressure is below its normal value at the time that the valve B is moved from .its release position, the vlocomotive brakes Will be again applied with a force corresponding to the amount of the train piperreduction.

ln non-holding position ofthe valve B, as shown in Fig. 5, ports c, t and d are freely connected and a'restricted passage ym joins them to port c which leads to the volume reservoir 7U. Thus it will be seen that chamber' 2 is 1in constant, direct communication with the train pipe and consequently the operation of the mechanism at the right of Fig. l will no longer be controllable in its release and holding position by thevalve A independently of the brakes on the cars of the train. This may,

of the volume reservoir, which might occur when an unusually high pressure is used in releasing the brakes (t. e. i'or recharging the train pipe), and, second;in order to stlll so restrict the flow of air from the volume reservoir (which may obviously pass to the train pipe through this port m and the passages above the cheek valve 75), that the piston 32 Will be moved upwardly when au emergency application is made.

In running position of the valve B, ports a, c, and d are freely connected `for the purpose explained in the description or the operation of valve A. The running position of the valve B is shown in Fig. l and also in Fig. 6.

In lap position ofthe valve B, as shown in Fig. 7, all the ports are closed with the exception of ports c and d which are simply connected, thus permitting' the pressure existing in the volume reservoir 7 0 to act on the piston 9 and thus enabling the engineer to held any desired cylinder pressure that he may have obtained, by a reduction of pressure in said reservoir.

In application position of the valve B, as shown in Fig. 8, ports c, d and e are connected, thus permitting oi' a reduction of pressure in the volume reservoir and chamber 2 and causing an application of the brakes, the amount of brake cylinder pressure obtained depending upon the extent otl the reduction of pressure in the volume reservoir and the chamber 2. The check valve now prevents a flow of air from the train pipe (through ducts 40, 37 and 74 and chamber 39, 31 and 72) to the volume reservoir 70 and thus makes possible the independent applieation and holding by the use of lap position of the brakes, on the locomotive and tender. It is also obvious, on the other hand, that in all positions of valve B, except release, a reduction of train pipe pressure below that in the volume reservoir will cause check valve 75 to rise and permit of a simultaneous reduction of pressure in said reservoir and consequently in chamber 2 (which is connected to the volume reservoir in all positions, except release, or' valve B) and this will therefore cause an application of the locomotive brakes, to the same extent as' these on the rest of the train. In order to prevent the valve B from being accidentally left in its release position (where the advantage just described is not obtained) some form of' automatic returning device may be employed to move the valve B from release to non-holding position; such a device may be operated by a spring or by air pressure or by both. A function (besides that of causing the operation of the piston 32 in emergency) et the volume reservoir 70 is therefore, to provide a means oi: increasing the volume ot air in chamber 2 in order to permit of the independent handling of the locomotive brakes with the use olI valves having parts of aj'ipreciable size, and to reduce to a minimum the cilieet or' slight leaks etc.,-it being undesirable to give a large volume ot' air to the chamber 2 directly as the [low of a large volume of air at a high pressure from such a chamber to the train pipe after an independent release of the locomotive brakes when the train pipe pressure. was below its normal point might result in the builling up of the train. pipe pressure to a point high enough to release the train brakes, which, would, o'lz course, be undesirable.

The check valve Si in the duet S() which conducts reduced supply pressure Huid to the valve A, serves to prevent a ilow oit air from the train pipe back to the supply pipe 7 9 at any time when ports al and b1 are connected and air is being drawn rapidly 'from pipe 79 to apply the locomotive brakes, as such a back flow would. mean a reduction ol" train pipe pressure below its normal value, which might be sullicient to cause an application of the train brakes and this would be an objectionable feature under certain conditions.

The cheek valve 86 is provided to furnish a means oi charging the main reservoir on dead engines (i. c. those, on which the compressors are inoperative) with air from the train pipe. This is ellectcd when the cock or plug valve 84 is turned so that port n; therein registers with the train pipe 20, and train pipe air is thus admitted to the duct 83 and thence by check 86 (which prevents a back flow) and ducts S5 and 7S and pipe 77 to the main reservoir. ln such position, of the cock 84 vthe duets leading from ports b1 and c1 are closed completely. )Vith the position of the cock S4 at 180 from that just described, the ducts b1 and c1 are closed, but there is no communication between the duct S3 and the train pipe. This is the position of the cock S4 on locomotives run as helpers when they have their own air supply. The object of this closing ducts 82 and SS on all locomotives run as helpers and or Hdead engines is to cut oi' all communication between the train pipe and valve A, and between port a (otvalve B) and valve A, and thus prevent the unwarranted operation el valve A vfrom influencing the train pipe pressure or that in the volume reservoir and chamber 2 in any way, and also to prevent other undesirable results which might occurif these` ducts (82 and 88) were not closed, under'the conditions stated.

Having fully described my invention what 1 claim as new and desire to secure by Letters- Patent, is

1. 1n an air brake apparatus, the combination with a valve mechanism to control supply pressure iiuid to the brake cylinders and the exhaust of Vthe same from said cylinders, of means for subjecting said valve mechanism to controlling pressure, means'for augmenting the volume of air actingupon the valve mechanism under controlling pressure, and means for controlling said volume augmenting means.

2. The combination in an air brake apparatus, oi two chambers a valve between said chambers for controlling` supply pressure to the brake cylinders, pistons in said chambers and connected with said Valve, means controlled by the movements of said pistons to control the brake cylinder exhaust, means for introducing train pipe fluid into one of said chambers at one side of the pistontherein, means for introducing air under a'diiierent vpressure into the same chamber on the same side of the said piston, means for subjecting the other side of the same piston-to supply pressure, and means for subjecting the piston in the otherchamber to cylinder pressure on one side and to'atmospheric pressure on the other side.

3. The combination in an airbrahe apparatus, of two chambers, a valve between said chambers for controlling supply pressure fluid to the brake cylinders, pistons in said chambers, means controlled by the movements of said vpistons to control the brake cylinder exhaust, two lmanually-operated Valves, means cooperating with both of said manually-operated valves for controlling, `by an operation otl either of them, the passage of train pipe pressure to and from one of said chambers at one side of the piston therein, means for subjecting the other side of the same piston to supply pressure, vand means for subjecting the piston in the other chamber to cylinder pressure on one side and to atmospheric pressure on the other side.

4. v1n an air brake apparatus, the combination with a valve mechanism `to control supply pressure iiuid to the brake cylinders and the exhaust of the same from said cylinders, of means for subjecting said Valve mechanism to train pipe pressure to control the same, a manually-operated Valve connected w'th said Valve mechanism and having ports and ducts to open and close communication of said valve mechanism with the train pipe, and to reduce controlling pressure in .said Valve mechanism `after communication of the latter with the trainpipe has been closed.

bination with valve :mechanism to control supply pressure iiuid tothe brake cylinders and the exhaust ofthe same from said cylinders, of means for subjecting said Valve mechanism to train pipe pressure to control the same, a manually-operated Valve connected with said Valve mechanism and haying ports and ductsfto open and close communication of said Valve mechanism with the train pipe, and'means controlled by said manually-operated valve to augment the said controlling Vpressure after communication of the Valve mechanism with the train pipe has been closed.

6. 1n an air braise apparatus, the combination with a valve mechanism to control supply pressure fluid to the brake cylinders i and the exhaust oi the same from said cylinders, oi two manually operated Valves,

means cooperating with bothoi said manu- Y for augmenting the Volume of air acting upon the Valve mechanism under controlling ressure and a manuall -o erated Valve device having ports and ducts to control the action of controlling pressure in said valve mechanism, and for controlling said Volume augmenting means.

8. 1n an air brake apparatus, the combination with a Valve for controlling the admission of pressure iluid to the brake cylinders and its exhaust therefrom, of controlling means for said valve, means for Ysubjecting said valve-controlling-means to train pipe pressure, means for shutting oil said train pipe pressure from said Valve-controllingmeans, and meansfor subjecting said Valvecontrolling-means to a di'erent pressure.

9. in an air brake apparatus, the combination with a valve for controlling the admission of pressure fluid to the brake cylinders and its exhaust therefrom, of controlling means for said Valve, means for subjecting said controlling-means to train pipe pressure, means for shutting ofi said train pipe pressure from said valve -controlling-means, means for subjecting said valVe-controlling-means to a different pressure, a Volume reservoir, and means ttor connecting said yVolume reservoir with the Valve-controlling-means to augment the Volumeof fluid which may be acting upon said valve-controlling-means.

l0. In an air brake apparatus, the combination with controlling means for supplying fluid to and exhausting it from the brake 5. 1n an air brake apparatus, the comcylinders, of a valve for closing admission of fluid to the brake cylinders, a chamber below said valve, a piston in said chamber subject to brake cylinder pressure and having a tubular upward extension, a rod depending from said valve and movable in said tubular extension from the iston, a s ring for opposing the action of tie cylinei' pressure on said piston, means for adjustingthe tension et' said spring, and means for venting brake cylinder pressure from the chamber containing the piston when the latter shall have been moved a predetermined distance by the action of said brake cylinder pressure.

11. In an air brake apparatus, the combination with controlling means for supplying fluid to and exhausting it from the brake cylinders, of a valve for closing admission or' fluid tothe brake cylinders, a cIiamber below said valve open to cylinder' pressure, a piston iii said chamber, means for causing movements of said piston to control said valve, adjustable means for opposing the movementsl of said piston by cylinder` pressure, and means for venting brake cylinder pressure from the chamber containing the piston' whenthe latter shall have been moved a redetermined distance by the action of brakeA cylinder pressure.

12. In an air brake apparatus, the combination with controlling means for supplying fluid to and exhausting it from the brake cylinders, of a' iston valve for closing admission oic fluir to the brake cylinders, a valve chamber in which said piston valve is movable, a spring tending to press said valve toward its seat, a chamber below said valve and its seat and open to cylinder pressure, a piston in said chamber, a movab e connection between said piston and the piston valve, an adjustable spring pressing against said piston and opposing the cylinder pressure acting upon said piston, and means for subjecting said piston valve to fluid pressure tending to oppose the seating of' the same.

13. In an air brake apparatus, the combination with controlling means for supplying fluid to and exhausting it from the brake cylinders, and means for regulating the cylinder ressure, of a passage to conduct train pipe uid to the brake cylinders, an emergency valve for closing said passage, operating means for said emergency valve, means for subjecting said valve-cperating-means to the action of train pipe pressure, means for simultaneously subjecting said valve-operatingmeans to fluid pressure derived from a source independent of train ipe pressure, and means controlled by said emergency valve-operating-means, for controlling the cylinder regulating means.

14. In an air brake apparatus, the combination with controlling means for supplying .fluid to and exhausting it from the brake cylinders, and means for regulating the cylinder iressure, of a passage to conduct train pipe "uid to the brake cylinders, an emergency valve for closing said passage, operating means for said emergency valve, means for subjecting said valve-operating means to the action of' train pipe pressure, means for simultaneously subjecting said valve-operating-means to fluid pressure derived from a source inde endent of train pipe pressure, means contro led by said emergency valveoperating-means, for controlling the cylinder pressure regulating means, a check valve located in said train pipe passage between the emergency valve and the brake cylinders.

15. In an air brake a paratus, the combination with a valve mecianism for supplying fluid to and exhausting it from the brake cylinders, of a volume reservoii, manually-controlled means for subjecting said valve mechanisni to controlling pressure from said volume reservoir, manually-operated means for charging said reservoir, means for communication between said volume reservoir and a train pipe, and a check valve iii said means of communication permitting of a flow of air from the volume reservoir to the ti'ain pipe.

16. In an air brake a paratus, the combination with a valve mec ianism for sup lying fluid to and exhausting it from the bra re cylinders, a train pipe, manually controlled means for subjecting said valve mechanism to controlling pressure, means orp communication between said manually-operated controlling means and a train pipe, and a check valve in said means of communication pervmittingl of a flow of' air to the train pipe.

17. n an air brake apparatus, the combination with a valve mechanism to control the supply of pressure fluid to and the exhaust of the same from the brake cylinders, a train pipe, and a fluid pressure supply pipe, of two manually operated valve devices, a duct tei'- minating at one end in a )ort under one manually operated valve and1 connected with the train pi e, a duct terminating at one end iii a port una er the saine manually operated valve and at the other end under the other manually operated valve, a manually operated cock for simultaneously opening or closing both of said ducts, and means of communication between said manually operated valve device and the fluid pressure supply pi e and between said manually operated va ve devices and the first mentioned valve mechanism.

18. In an air brake apparatus, the combination with a valve mechanism to control the supply of pressure fluid to and the exhaust of the same from the brake cylinders, a train pipe, and a fluid pressure supply pipe, of two manually operated valve devices, a duct terminating at one end in a )ort under one maiiually operated valve anc connected with the train pipe, a duct terminating at one end in a port under the saine manually operated Valve and at the other end under the other Vmanually operated Valve, a manually operated cock for simultaneously opening o1'` closing both of said ducts, and means of communication between said manually operated Valve device and the fluid pressure supply pie and between said manually operated V'allve devices and the first mentioned Valve mechanism, and means controlled by said manually operated cock for opening communication between the train pipe and supply i'luid. reservoir of a dead7 engine fol charging said reservoir.

19. In an air brake apparatus7 the combination with a Valve mechanism to control supply pressure fluid to the brake cylinders andthe exhaust of the same from said cylinders, of two manually e operated Valves, means copelating with both of said manually-opeated Valves for. controlling, by an operation of either of them, the-passage of` operated Valves for controllingv the piessure 25 of train pipe Huid.

In testimony whereof, I have signed this specification in the presence of two subscriblngl witnesses.

HONARD M. P; MURPHY.

Witnesses A. N.. MITCHELL,l R. S. FERGUSON. 

